print() in isolate in dartium does not output to console.log

[sethladd]

The print() method, if run from an isolate in dartium, does not print to console.log.

[DartBot]

This comment was originally written by antonm@google.com

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Seth,

you mean pure Dart, not DOM-enabled isolate?

If yes, it's be design, but we may want to change it later.

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Set owner to antonm@google.com.
Added NeedsInfo label.

[sethladd]

Hi Anton, thanks for taking a look.

This was testing print() inside a function running from spawnFunction.

It's not apparent that print won't work from spawnFunction inside Dartium. It would be nice to minimize the differences in behavior between different Dart environments.

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Added Triaged label.

[DartBot]

This comment was originally written by antonm@google.com

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Thanks, Seth.

That's definitely true, but at least that's not some problem we are not aware of. We'll fix it later.

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Added this to the Later milestone.
Removed Type-Defect label.
Added Type-Enhancement label.

[DartBot]

This comment was originally written by Ruper...@gmail.com

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Clarification request: What do "pure Dart" and "DOM-enabled isolate" mean?

(especially does it imply there actually is a way to get print() and stack-trace output from child isolate in Dartium?)

[DartBot]

This comment was originally written by antonm@google.com

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Rupert,

Not all isolates can access DOM for various reasons. For example, due to the way WebKit is implemented to access DOM isolate should leave on the main UI thread. Therefore we have a distinction between pure isolates---isolates which thread-affinity is not restricted, but which cannot really access DOM---and DOM-enabled isolates---which must live on the same thread, but which can access DOM in return.

Does that make sense?

[DartBot]

This comment was originally written by Ruper...@gmail.com

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Thanks for the speedy response!

So is this the "Light" and "Heavy" Isolates from https://groups.google.com/a/dartlang.org/forum/m/?fromgroups#!topic/misc/NGHcDh_9MUg ?
So is the following fair:

• heavy = pure = true multi-thread (i.e. WebWorker once dart2js + Issue dart2js not using web worker for isolate #4689 done) vs
• light = "DOM-enabled isolates" = simulated MT (Java 1.0's 'green threads').

Where can I find documentation about this? (I must be missing from both the language tour Isolates section and the Isolates API doc.) (e.g. How do I create light vs heavy? Can I switch between light until debugged, then heavy for real MT?)

TIA

[DartBot]

This comment was originally written by Rupert...@gmail.com

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Answered the "how" myself through searching:
http://api.dartlang.org/docs/continuous/dart_html.html#spawnDomFunction
(Curious that neither of my previously referenced docs reference this -- docs bug?)
Coded-up a way to easily switch.

Still interested to know whether my 'heavy' vs. 'light' summary is accurate if possible!
TIA

[DartBot]

This comment was originally written by Rupert.K...@gmail.com

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p.s. Just to note: print() successfully outputs to console when using DOM isolate as do exceptions (logging to console and breaking into debugger) but breakpoints still don't work in spawned isolate (with DOM or pure, Dartium or Dart VM).

[DartBot]

This comment was originally written by antonm@google.com

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Yes, Rupert, that's exactly original distinction between heavy/light. We just decided to drop it into favour of more straightforward descriptions.

And thanks a lot for bringing the case of debugging pure isolates, we need to imprtove support for those. I'll file a separate bug.

[DartBot]

This comment was originally written by Rupert.K...@gmail.com

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Great! Please CC me on the new issue(s). Thanks!

[DartBot]

This comment was originally written by antonm@google.com

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Set owner to podivilov@google.com.
Removed this from the Later milestone.
Added this to the M3 milestone.

[DartBot]

This comment was originally written by antonm@google.com

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See http://code.google.com/p/dart/issues/detail?id=5620

[DartBot]

This comment was originally written by antonm@google.com

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Issue #4891 has been merged into this issue.

[anders-sandholm]

Removed this from the M3 milestone.
Added this to the M4 milestone.

[DartBot]

This comment was originally written by antonm@google.com

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Set owner to antonm@google.com.